<?php

/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Select
 * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Select.php 24593 2012-01-05 20:35:02Z matthew $
 */
/**
 * @see Zend_Db_Select
 */
require_once 'Zend/Db/Select.php';


/**
 * @see Zend_Db_Table_Abstract
 */
require_once 'Zend/Db/Table/Abstract.php';

/**
 * Class for SQL SELECT query manipulation for the Zend_Db_Table component.
 *
 * @category   Zend
 * @package    Zend_Db
 * @subpackage Table
 * @copyright  Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Db_Table_Select extends Zend_Db_Select {

	/**
	 * Table schema for parent Zend_Db_Table.
	 *
	 * @var array
	 */
	protected $_info;

	/**
	 * Table integrity override.
	 *
	 * @var array
	 */
	protected $_integrityCheck = true;

	/**
	 * Table instance that created this select object
	 *
	 * @var Zend_Db_Table_Abstract
	 */
	protected $_table;

	/**
	 * Class constructor
	 *
	 * @param Zend_Db_Table_Abstract $adapter
	 */
	public function __construct(Zend_Db_Table_Abstract $table) {
		parent::__construct($table->getAdapter());

		$this->setTable($table);
	}

	/**
	 * Return the table that created this select object
	 *
	 * @return Zend_Db_Table_Abstract
	 */
	public function getTable() {
		return $this->_table;
	}

	/**
	 * Sets the primary table name and retrieves the table schema.
	 *
	 * @param Zend_Db_Table_Abstract $adapter
	 * @return Zend_Db_Select This Zend_Db_Select object.
	 */
	public function setTable(Zend_Db_Table_Abstract $table) {
		$this->_adapter = $table->getAdapter();
		$this->_info = $table->info();
		$this->_table = $table;

		return $this;
	}

	/**
	 * Sets the integrity check flag.
	 *
	 * Setting this flag to false skips the checks for table joins, allowing
	 * 'hybrid' table rows to be created.
	 *
	 * @param Zend_Db_Table_Abstract $adapter
	 * @return Zend_Db_Select This Zend_Db_Select object.
	 */
	public function setIntegrityCheck($flag = true) {
		$this->_integrityCheck = $flag;
		return $this;
	}

	/**
	 * Tests query to determine if expressions or aliases columns exist.
	 *
	 * @return boolean
	 */
	public function isReadOnly() {
		$readOnly = false;
		$fields = $this->getPart(Zend_Db_Table_Select::COLUMNS);
		$cols = $this->_info[Zend_Db_Table_Abstract::COLS];

		if (!count($fields)) {
			return $readOnly;
		}

		foreach ($fields as $columnEntry) {
			$column = $columnEntry[1];
			$alias = $columnEntry[2];

			if ($alias !== null) {
				$column = $alias;
			}

			switch (true) {
				case ($column == self::SQL_WILDCARD):
					break;

				case ($column instanceof Zend_Db_Expr):
				case (!in_array($column, $cols)):
					$readOnly = true;
					break 2;
			}
		}

		return $readOnly;
	}

	/**
	 * Adds a FROM table and optional columns to the query.
	 *
	 * The table name can be expressed
	 *
	 * @param  array|string|Zend_Db_Expr|Zend_Db_Table_Abstract $name The table name or an
	  associative array relating
	  table name to correlation
	  name.
	 * @param  array|string|Zend_Db_Expr $cols The columns to select from this table.
	 * @param  string $schema The schema name to specify, if any.
	 * @return Zend_Db_Table_Select This Zend_Db_Table_Select object.
	 */
	public function from($name, $cols = self::SQL_WILDCARD, $schema = null) {
		if ($name instanceof Zend_Db_Table_Abstract) {
			$info = $name->info();
			$name = $info[Zend_Db_Table_Abstract::NAME];
			if (isset($info[Zend_Db_Table_Abstract::SCHEMA])) {
				$schema = $info[Zend_Db_Table_Abstract::SCHEMA];
			}
		}

		return $this->joinInner($name, null, $cols, $schema);
	}

	/**
	 * Performs a validation on the select query before passing back to the parent class.
	 * Ensures that only columns from the primary Zend_Db_Table are returned in the result.
	 *
	 * @return string|null This object as a SELECT string (or null if a string cannot be produced)
	 */
	public function assemble() {
		$fields = $this->getPart(Zend_Db_Table_Select::COLUMNS);
		$primary = $this->_info[Zend_Db_Table_Abstract::NAME];
		$schema = $this->_info[Zend_Db_Table_Abstract::SCHEMA];


		if (count($this->_parts[self::UNION]) == 0) {

			// If no fields are specified we assume all fields from primary table
			if (!count($fields)) {
				$this->from($primary, self::SQL_WILDCARD, $schema);
				$fields = $this->getPart(Zend_Db_Table_Select::COLUMNS);
			}

			$from = $this->getPart(Zend_Db_Table_Select::FROM);

			if ($this->_integrityCheck !== false) {
				foreach ($fields as $columnEntry) {
					list($table, $column) = $columnEntry;

					// Check each column to ensure it only references the primary table
					if ($column) {
						if (!isset($from[$table]) || $from[$table]['tableName'] != $primary) {
							require_once 'Zend/Db/Table/Select/Exception.php';
							throw new Zend_Db_Table_Select_Exception('Select query cannot join with another table');
						}
					}
				}
			}
		}

		return parent::assemble();
	}

}